Insulating panel and closure



r O f. n e D n 3 B. E. CLATWORTHY INSULATING PANEL AND CLOSURE Filed Aug. 51, 193

Oct. 4, 1 938.

Patented Oct. 4, 1938 UNITED STATES PATENT OFFICE INSULATING PANEL AND CLOSURE Buell E. Clatworthy, Haddon Heights, N. J., assignor to Radio Corporation of America, a corance.

poration of Delaware Application August 31, 1936, Serial No. 98,833

3 Claims.- (Cl. 24726) This invention relates to insulating panels and closures, particuarly to panels and closures for receptacles commonly used in electric signaling apparatus and has special reference to the provision ofa snap-on closure having knock-out sections and comprising a unit suitable for use in a wide variety of applications without sacrifice to either its insulating properties or neat appear- While the invention will be described in connection with a receptacle designed to accommodate a relatively small electrical unit, such for instance'as an audio transformer, for use in radio receivers, it is to be understood that the invention is not to be limited to such application as the disclosure, in this respect, is merely illustrative for purposes of explaining the inventive concept. In radio and photophone apparatus it is usual to mount one or more transformer receptacles or cans upon a sub-panel and to mount the sub-panel and its assembly asa unit on the supporting frame or chassis of the set; In addition to forming a convenient support the sub-panel serves as a closure for the otherwise open receptacle or receptacles.

In attaching one of such receptacles to its sub-panel several operations are required; thus, holes must be drilled in the panel, rivets must be provided for holding the receptacle to the sub-panel, and the rivets inserted in the holes and riveted over.

An object of the present invention is to provide a simple, inexpensive and trouble-free transformer or like casing and a closure or sub-panel therefor, which closure can be snapped into position and held securely without drilling and riveting.

In accordance with the prior art, a plurality of additional holes must be drilled in the sub-panel to accommodate the electrical leads to the enclosed device; further, these holes must differ in number and arrangement as determined by the terminal connections required for each individual device so that it is not practical to provide a standard number or arrangement of lead-holes.

Another object, therefore, of the invention is to provide a universal closure adapted to accommodate any desired number or pattern of leadholes without drilling or boring.

A further object of the invention is to provide an insulating panel adapted to accommodate any desired number of electrical terminal elements in spaced rigid alignment.

and the chassis of the set.

This in effect provides an air-gap in a magnetic circuit and does not permit of perfect transformer shielding.

A still further object'of the present invention is to provide a transformer casing and closure therefor, constituting a perfect magnetically shielded assembly.

Otherobjects and advantages will be apparent and the invention itself will be best understood by reference to the following specification and the accompanying drawing, wherein i Fig. 1 is a bottom plan view of an insulating closure or panel constructed in accordance with the invention,

Fig. 2 is a side elevation or edge View of the closure of Fig. 1,

Fig. 3 is a sectional View taken on the line 33 of Fig. 1, i

Fig. 4 is an enlarged fragmentary view of the closure, showing a terminal connection aflixed thereto, 7

Fig. 5 is a sectional View of an extruded type of eyelet suitable for use as a terminal connection,

Fig. 6 is a fragmentary sectional view of a receptacle and closure therefor, assembled and with a terminal in place, and

Fig. 7 is a bottom plan View of thereceptacle and closure, mounted, and having terminal connections arranged in a desired pattern.

Like reference characters represent the same or corresponding parts in all figures.

- In the drawing 2 designates generally a molded panel, panel insert, base or closure formed of hard rubber, synthetic resin or other insulating compound. The body of Z is designated 3 and its outer and inner surfaces 6 and 8, respectively. Member 2 is shown as a circular disc; it may, however, be of any desired shape or of any dimensions, as determined by the particular use for which it is designed. As shown in Fig. 6 where the panel is designed to constitute a closure for a transformer or like receptacle R the body portion 4 is preferably provided with a beveled peripheral edge or rim Ill directed downwardly and inwardly from its outer surface 6. The disc is further provided about its edge, preferably intermediate its outer surfaces 6 and 8, with a plurality of diametrically opposite beveled protuberances or lips l2 and I2 which are adapted to engage complementary detents M on the inner surface of the receptacle R. The metal of which R is formed will be understood to be flexible enough to allow the insertion of the protuberances l2 in the detents l4 thereby permitting the closure to be inserted in the mouth of the receptacle, flush with the rim, by a snap-on move- Cir ment. If desired the engaged and engaging members I2 and I 4 may extend around all, or substantially all, of the circumference of the closure and receptacle. The closure may further be provided with a pair of inwardly beveled opposite slots [6 and I6 into which a pair of sharp edge tools (not shown) may be inserted to facilitate removal of the closure for purposes of inspection and repair of the device (not shown) within the receptacle.

As more clearly shown in Figs. 3 and 4, the body 4 of the panel is provided with a plurality of molded recesses in its inner surface. Each recess comprises an upper counter-sunk portion 26, a shoulder portion 22 and a-knock-out section 24 of reduced diameter which extends almost entirely through the body of the insulating material.

When a knock-out section 24 is struck a sharp blow with a suitable instrument (not shown) the disc, which aperture is adapted to receive a suit able terminal connecting element.

Figs 4 to 7, inclusive, show a suitable terminal connecting-element comprising a U-shape member 28 provided in the U with an extruded eyelet 30 which forms a miniature conduit through which a lead wire 34 (Fig. 6)- may extend; from the interior to the exterior of the receptacle R. The terminal 28 may be fastened to the disc or panel by riveting the eyelet30 over the shouldered surface 22 of the recess which' surrounds the knock-out section 24. The wire or lead 34 may be connected to one or the other of the upstanding arms 32 of the U-shape element, in any suitable or convenient manner.

, Referring again to Figs.-1 and 3: The reduced diameter portion of the recesses, which constitute the knock-out sections 24, may be arranged in any suitable pattern; preferably, however, they are symmetrically arranged and molded in spaced parallel rows; for example, as shown more clearly in Fig. 1. The surface 6 opposite the surface 8 in which the recesses are molded is provided with a plurality of raised portions or ridges 36 parallel to and spaced from the axis of each row of the recessed knock-out sections 24. Thus an orifice 26 formed by knocking out one of the knock-out sections 24 will lie, in the case of the outer rows, adjacent an end. ridge 36,

'and'in the case of the inner rows 36', between two ridges. The terminal connecting elements 28, see Fig. '7 nest snugly against one, or between two, of these ridges 36 so that if there should be any tendency towards lateral displacement or movement of a connecting element such movement will be prevented by the ridge or ridges against which or between which, said element is positioned. If the surface about an orifice is frayed in its formation by the knock-out blow the ridges 36 serve by their very presence to limit the frayed area. Such fraying as may take place between or adjacent these ridges is eifectively concealed by the ,U -portion of the connecting element about the orifice.

A preferred manner of attaching a receptacle including a sub-panel or closure of the invention to a main panel or chassis is shown in Fig. 7. The main panel which is preferably of metal is designated 40 and is provided with an orifice 42 of the same size and shape as that of the body of the sub-panel 2. The receptacle R is shown provided with corner flanges suitably orificed to receive bolts b which extend through the main panel 46 to the under side thereof. The bolts b? are threaded to receive nuts n. So mounted the metal receptacle R is attached directly to the metal of the main panel or chassis 40 without any intervening insulation. As previously set forth, such insulation if presentwould constitute a virtual air-gap in a magnetic circuit and would inhibit perfect magnetic shielding of the device contained withinthe receptacle.

As a number of possible embodiments may be made of the above invention, and as changes may be made in the described embodiment without departing from the spirit and scope of'the invention, it is to be understood that the foregoing is to be interpreted as illustrative and not in a limiting sense except as required by. the appended claims and by the prior art.

What is claimed is: p

1. A sub-panel or closure for electrical-unit receptacles comprising a molded base'of insulating material formed with a knock-out section in.

plurality of spaced parallel ridges on the outer side of said base between said rows of knock-out sections.

3. An insulating closure for electrical-unit receptacles, said closure having a plurality of re cessed knock-out sections arranged in spaced parallel rows in one surface thereof, a ridge on the opposite side of said base between said rows of knock-out sections, and means for removably seating said closure in a receptacle with its ridged surface exposed.

BUELL E. CLATWORTHY. 

